Parallels Desktop Virtual Machine is one way to get a Windows experience on a Mac but it can also cause charging problems as seen with the Apple 15" MacBook Pro (2018). While Parallels VM was running on the Mac, we connected the Mac at 1% battery charge to AC power through the Apple 29W USB-C Power Adapter. However no charging actually happened as observed over USB Power Delivery between the Mac and Apple charger.

Although current was pulled from initial plugin, the power charging kept on resetting over repeated intervals which did not allow the Mac to charge with the Apple charger. More details can be seen here by downloading the trace captured by the GRL-A1 power analyzer.